BUCKINGHAM AND NORMANBY, JOHN SHEFFIELD,1st Duke of (1648–1721), English statesman and poet, was born on the 7th of April 1648. He was the son of Edmund, 2nd earl of Mulgrave, and succeeded to that title on his father's death in 1658. At the age of eighteen he joined the fleet, to serve in the first Dutch war; on the renewal of hostilities in 1672 he was present at the battle of Southwold Bay, and in the next year received the command of a ship. He was also made a colonel of infantry, and served for some time under Turenne. In 1680 he was put in charge of an expedition sent to relieve the town of Tangier. It was said that he was provided with a rotten ship in the hope that he would not return, but the reason of this abortive plot, if plot there was, is not exactly ascertained. At court he took the side of the duke of York, and helped to bring about Monmouth's disgrace. In 1682 he was dismissed from the court, apparently for putting himself forward as a suitor for the princess Anne, but on the accession of King James he received a seat in the privy council, and was made lord chamberlain. He supported James in his most unpopular measures, and stayed with him in London during the time of his flight. He also protected the Spanish ambassador from the dangerous anger of the mob. He acquiesced, however, in the Revolution, and in 1694 was made marquess of Normanby. In 1696 he refused in company with other Tory peers to sign an agreement to support William as their "rightful and lawful king" against Jacobite attempts, and was consequently dismissed from the privy council. On the accession of Anne, with whom he was a personal favourite, he became lord privy seal and lord-lieutenant of the North Riding of Yorkshire, and in 1703 duke of Buckingham and Normanby. During the predominance of the Whigs between 1705 and 1710, Buckingham was deprived of his office as lord privy seal, but in 1710 he was made lord steward, and in 1711 lord president of the council. After the death of Anne he held no state appointment. He died on the 24th of February 1721 at his house in St James's Park, which stood on the site of the present Buckingham Palace. Buckingham was succeeded by his son, Edmund (1716-1735) on whose death the titles became extinct.

Buckingham, who is better known by his inherited titles as Lord Mulgrave, was the author of "An Account of the Revolution" and some other essays, and of numerous poems, among them the Essay on Poetry and the Essay on Satire. It is probable that the Essay on Satire, which attacked many notable persons, "sauntering Charles" amongst others, was circulated in MS. It was often attributed at the time to Dryden, who accordingly suffered a thrashing at the hands of Rochester's bravoes for the reflections it contained upon the earl. Mulgrave was a patron of Dryden, who may possibly have revised it, but was certainly not responsible, although it is commonly printed with his works. Mulgrave adapted Shakespeare's Julius Caesar, breaking it up into two plays, Julius Caesar and Marcus Brutus. He introduced choruses between the acts, two of these being written by Pope, and an incongruous love scene between Brutus and Portia. He was a constant friend and patron of Pope, who expressed a flattering opinion of his Essay on Poetry. This, although smoothly enough written, deals chiefly with commonplaces.

In 1721 Edmund Curll published a pirated edition of his works, and was brought before the bar of the House of Lords for breach of privilege accordingly. An authorized edition under the superintendence of Pope appeared in 1723, but the authorities cut out the "Account of the Revolution" and "The Feast of the Gods" on account of their alleged Jacobite tendencies. These were printed at the Hague in 1727. Pope disingenuously repudiated any knowledge of the contents. Other editions reappeared in 1723, 1726, 1729, 1740 and 1753. His Poems were included in Johnson's and other editions of the British poets.